In 1966, Florence was hit by a terrible flood that destroyed streets, monuments and extremely valuable works of art. This tragic event destroyed the entire city’s lighting system, which had to be redesigned, with a faithful reproduction of the square lantern, originally a gas-powered model, that had provided light to streets and squares since the 1800s. Currently, thousands of lanterns of this type provide light to the city. During the past few years, Neri has often worked closely with Silfi, Florence’s electric company, which has been managing the city’s lighting for almost half a century. Solutions were researched that could safeguard aesthetics and tradition, while also improving energy savings, visual comfort and general efficiency of the lanterns installed. The final result of this research can now be admired on the streets of Florence. The solution has prevented lanterns installed in the 1970s from being replaced with similar, latest generation products. Instead, the preferred course of action involved keeping and restoring the existing lanterns. They were upgraded with the latest technology to achieve considerable savings and better visual comfort, which is crucial for such an important city. Neri was entrusted with the technological research for this project, carried out at their corporate laboratories, and also with the restoration.

Since the lanterns were made in brass sheet, cleaning them without treating them and letting their finish weather with time was the preferred solution. All screens were replaced and the basic screen was adorned with the red lily of Florence. The technological upgrading and enhanced efficiency coincided with the elimination of the visible light source. Instead a kit in the upper part of the lantern that contained asymmetrical diffuser and the various wiring components has been installed. All equipment is no longer visible as it was in the past. In the original lantern, before the intervention, light reflected on the walls and above the lantern. Even though the intention was to reduce this effect and the resulting skyward light dispersion, it has been agreed to keep a partial orientation towards the upper part of the lantern to preserve Florence’s characteristic nocturnal atmosphere and to fully appreciate the shape of the lamp. To obtain this, Neri designed a flat sheet metal surface that contains the optical block and wiring, and presents a series of openings to filter the desired amount of light. The effects were then tested with a photometric analysis in the Neri laboratories.

The process produced important results both on a lighting engineering level and in terms of savings:

1. The average lighting value was three times greater than the previous configuration
2. Energy savings were over 50%.

The kit with its openings on the flat part, the trapezoidal box containing the optical block, and the wall that can be lowered to change the bulb were all registered with patent n. BO2013U000109. Today, Florence is lit with traditional lanterns, but with a new efficient, comfortable and cost-effective light. It is interesting to compare the results obtained, against those of the previous lighting system, with the new system that uses cool light to fight glare.